New simple tests for age-at-onset anticipation: application to panic disorder

Area of Science:

• Biostatistics
• Genetics
• Psychiatry

Background:

• Anticipation, the phenomenon of earlier age of onset in successive generations, is of renewed interest.
• Standard statistical methods are unsuitable for analyzing anticipation due to sampling bias.
• Existing tests for comparing parental and child ages of onset are computationally complex and lack software support.

Purpose of the Study:

• To develop novel, accessible statistical tests for analyzing anticipation.
• To address the bias introduced by right-censored age of onset data in generational studies.
• To provide practical tools for researchers studying genetic anticipation.

Main Methods:

• Formulating anticipation testing as a problem of symmetry.
• Proposing a generalized paired t-test and a Wilcoxon signed rank test adjusted for right truncation.
• Extending the generalized paired t-test to a random effects model for analyzing correlated family data.

Main Results:

• The proposed symmetry tests effectively adjust for right truncation bias in age of onset data.
• The generalized paired t-test and Wilcoxon signed rank test offer simpler alternatives to existing methods.
• The random effects model accommodates correlated data within nuclear families, with potential for broader family structures.

Conclusions:

• The developed statistical methods provide a more accessible and accurate approach to testing for anticipation.
• These methods can be applied to various genetic disorders with anticipation, such as panic disorder.
• The proposed framework facilitates the analysis of genetic anticipation in familial contexts.